q.1 i. atomic number
TRANSCRIPT
Answer:i. Atomic Number – Denotes number of
electrons & protons.
ii. Atomic Mass – Denotes number of
nucleons.
1. Matter has mass and takes up space.
2. Atoms are basic building blocks of matter, and cannot be chemically subdivided by ordinary means.
3. Even though an atom is really small, it is made of even smaller particles.
4. It’s made of 3 tiny subatomic particles:
i. Protons.
ii. Neutrons.
iii. Electrons.
• A substance composed of a single kind of atom.
• Cannot be broken down into another substance by chemical or physical means.
• Smallest part of an element is an ATOM.
• Example: Hydrogen, Carbon, Sodium, Magnesium etc.,.
• A substance in which two or more different elements are CHEMICALLY bonded together.
• Example: Water, Ammonia, Methane, Carbon Dioxide etc.,.
• Two or more substances that are mixed togetherbut are NOT chemically bonded.
• Example: Air, Water in Oil, Ice in Water etc.,.
• The number of protons found in the nucleus of an atom.
OR
• The number of electronssurrounding the nucleus of an atom.
• Number of PROTONS = ATOMIC NUMBER
• Number of ELECTRONS = ATOMIC NUMBER
• Number of NEUTRONS = ATOMIC MASS – ATOMIC NUMBER
• In 1869, Dmitri Ivanovitch Mendeléev created the firstaccepted version of the periodic table.
• He grouped elements according to their atomic mass, and as he did, he found that the families had similar chemical properties.
• THE PHYSICAL AND CHEMICAL PROPERTIES OF ELEMENTS ARE PERIODIC FUNCTION OF THEIR ATOMIC MASSES.
• Blank spaces were left open to add the new elementshe predicted would occur (& to maintain periodicity).
• As a result, he was able to classify 63 elements known at that time.
• Henry Moseley, in 1913, showed that the frequency of X-Ray emitted by an element is related to its Atomic Number (Z).
• Thus, he modified the periodic law given by Mendeléev.
• THE PHYSICAL AND CHEMICAL PROPERTIES OF ELEMENTS ARE A PERIODIC FUNCTION OF THEIR ATOMIC NUMBERS.
• Long form or the modern period table consists of 118 elements spread across:
i. 7 horizontal rows called as PERIODS (numbered 1 to 7).
ii. 18 vertical columns called as GROUPS (numbered 1 to 18).
• Below the main table are placed two series (Lanthanides & Actinides) containing fourteen elements each.
• Furthermore, it is divided into 4 blocks.
• Group 1 & 2 -> S block.
• Group 3 to 12 -> D block.
• Group 13 to 18 -> P block.
• Two series placed @ bottom -> F block.
• Metals are good conductors of heat and electricity.
• Metals are shiny.
• Metals are ductile (can be stretched into thin wires).
• Metals are malleable (can be pounded into thin sheets).
• A chemical property of metal is its reaction with water which results in corrosion.
• Non-metals are poor conductors of heatand electricity.
• Non-metals are not ductile or malleable.
• Solid non-metals are brittle and break easily.
• They are dull.
• Many non-metals are gases.
Sulfur
• Metalloids (metal-like) have properties of both metals and non-metals.
• They are solids that can be shiny or dull.
• They conduct heat and electricity better than non-metals but not as well as metals.
• They are ductile and malleable.
SILICON
• Happy Heman Likes Beer But Could Not Obtain it for Free isiliye NeeNa se Maanga, AlSi Paise so She Called Arjun KaCa
• Elements covered = H, He, Li, Be, B, C, N, O, F, Ne, Na, Mg, Al, Si, P, S, Cl, Ar, K, Ca.
B2p1
1IA
18VIIIA
12
IIA13
IIIA14
IVA15VA
16VIA
17VIIA
2
33
IIIB4
IVB5
VB6
VIB7
VIIB8 9
VIIIB10 11
IB12IIB
4
5
6
7
H
1s1
Li
2s1
Na
3s1
K
4s1
Rb
5s1
Cs
6s1
Fr
7s1
Be
2s2
Mg
3s2
Ca
4s2
Sr
5s2
Ba
6s2
Ra
7s2
Sc
3d1
Ti
3d2
V
3d3
Cr
4s13d5
Mn
3d5
Fe
3d6
Co
3d7
Ni
3d8
Zn
3d10Cu
4s13d10
B
2p1
C
2p2
N
2p3
O
2p4
F
2p5
Ne
2p6
He
1s2
Al
3p1
Ga
4p1
In
5p1
Tl
6p1
Si
3p2
Ge
4p2
Sn
5p2
Pb
6p2
P
3p3
As
4p3
Sb
5p3
Bi
6p3
S
3p4
Se
4p4
Te
5p4
Po
6p4
Cl
3p5
Be
4p5
I
5p5
At
6p5
Ar
3p6
Kr
4p6
Xe
5p6
Rn
6p6
Y
4d1
La
5d1
Ac
6d1
Cd
4d10
Hg
5d10
Ag5s14d10
Au6s15d10
Zr
4d2
Hf
5d2
Rf
6d2
Nb
4d3
Ta
5d3
Db
6d3
Mo
5s14d5
W
6s15d5
Sg
7s16d5
Tc
4d5
Re
5d5
Bh
6d5
Ru
4d6
Os
5d6
Hs
6d6
Rh
4d7
Ir
5d7
Mt
6d7
Ni
4d8
Ni
5d8